<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<style type="text/css">
		*{
			margin: 0;
			padding: 0;
		}
		img{
			width: 150px;
			height: 150px;
		}
		.box{
			text-align: center; /*水平居中*/
			padding-top: 30px;
			padding-bottom: 30px;
			background-color: rgba(95, 129, 172, 0.6);
		}
		body{
			background-image: url("images/1.jpg");
			background-repeat: no-repeat; /*防止图像平铺*/
			background-size: cover; /* 图片铺满整个body*/
		}
	</style>
	<body>
		<div class="box">
			<img src="images/1.jpg">
			<img src="images/2.jpg">
			<img src="images/3.jpg">
			<img src="images/4.jpg">
			<img src="images/5.jpg">
		</div>

		
		<script type="text/javascript">
			window.onload = function() {
				var images = document.getElementsByTagName('img');
				for (let i = 0; i < images.length; i++) {
					images[i].onclick = function () {
						//this 代表当前正在点击的对象
						var imageSrc = this.src;
						//document.body.style.backgroundImage = 'url("images/2.jpg")'
						document.body.style.backgroundImage = 'url("'+imageSrc+'")'
					}
				}
			}
		</script>
	</body>
</html>
